I found this New York Times article fascinating in a repulsive sort of way...

February 13, 2009 Op-Ed Contributor

The Maggots in Your Mushrooms

By E. J. LEVY

THE Georgia peanut company at the center of one of our nation’s worst food-contamination scares has officially reached a revolting new low: a recent inspection by the Food and Drug Administration discovered that the salmonella-tainted plant was also home to mold and roaches.

You may be grossed out, but insects and mold in our food are not new. The F.D.A. actually condones a certain percentage of “natural contaminants” in our food supply — meaning, among other things, bugs, mold, rodent hairs and maggots.

In its (falsely) reassuringly subtitled booklet “The Food Defect Action Levels: Levels of Natural or Unavoidable Defects in Foods That Present No Health Hazards for Humans,” the F.D.A.’s Center for Food Safety and Applied Nutrition establishes acceptable levels of such “defects” for a range of foods products, from allspice to peanut butter.

Tomato juice, for example, may average “10 or more fly eggs per 100 grams [the equivalent of a small juice glass] or five or more fly eggs and one or more maggots.” Tomato paste and other pizza sauces are allowed a denser infestation — 30 or more fly eggs per 100 grams or 15 or more fly eggs and one or more maggots per 100 grams.

Canned mushrooms may have “over 20 or more maggots of any size per 100 grams of drained mushrooms and proportionate liquid” or “five or more maggots two millimeters or longer per 100 grams of drained mushrooms and proportionate liquid” or an “average of 75 mites” before provoking action by the F.D.A.

The sauerkraut on your hot dog may average up to 50 thrips. And when washing down those tiny, slender, winged bugs with a sip of beer, you might consider that just 10 grams of hops could have as many as 2,500 plant lice. Yum.

Giving new meaning to the idea of spicing up one’s food, curry powder is allowed 100 or more bug bits per 25 grams; ground thyme up to 925 insect fragments per 10 grams; ground pepper up to 475 insect parts per 50 grams. One small shaker of cinnamon could have more than 20 rodent hairs before being considered defective.

Peanut butter — that culinary cause célèbre — may contain approximately 145 bug parts for an 18-ounce jar; or five or more rodent hairs for that same jar; or more than 125 milligrams of grit.

In case you’re curious: you’re probably ingesting one to two pounds of flies, maggots and mites each year without knowing it, a quantity of insects that clearly does not cut the mustard, even as insects may well be in the mustard.

The F.D.A. considers the significance of these defects to be “aesthetic” or “offensive to the senses,” which is to say, merely icky as opposed to the “mouth/tooth injury” one risks with, for example, insufficiently pitted prunes. This policy is justified on economic grounds, stating that it is “impractical to grow, harvest or process raw products that are totally free of non-hazardous, naturally occurring, unavoidable defects.”

The most recent edition of the booklet (it has been revised and edited six times since first being issued in May 1995) states that “the defect levels do not represent an average of the defects that occur in any of the products — the averages are actually much lower.” Instead, it says, “The levels represent limits at which F.D.A. will regard the food product ‘adulterated’ and subject to enforcement action.”

Bugs in our food may not be so bad — many people in the world practice entomophagy — but these harmless hazards are a reminder of the less harmless risks we run with casual regulation of our food supply. For good reason, the F.D.A. is focused on peanut butter, which the agency is considering reclassifying as high risk, like seafood, and subjecting it to special safety regulations. But the unsettling reality is that despite food’s cheery packaging and nutritional labeling, we don’t really know what we’re putting into our mouths.

Soup merits little mention among the products listed in the F.D.A.’s booklet. But, given the acceptable levels for contaminants in other foods, one imagines that the disgruntled diner’s cri de coeur — “Waiter, there’s a fly in my soup!” — would be, to the F.D.A., no cause for complaint.

E. J. Levy is a professor of creative writing at the University of Missouri